What's a good way to manage the Local Notifications your app has scheduled?

Question

I'm diving into iOS development and have been working on an alarm clock app to become familiar with iOS platform and SDK. I'm using Local Notifications to handle my alarms, but I need some method of managing the Local Notifications I set so that they can be updated if I edit or remove any of the alarms associated with them. I figured out how I can unschedule a Local Notification using cancelLocalNotification: function after it's been scheduled, but I'm having a hard time figuring out how to retrieve the Local Notification object associated with the alarm that was edited or removed so that I can use that function. I should note that all of my alarm objects that are used to create the Local Notifications are being stored in a Core Data DB and their interface is defined as...

@interface Alarm :  NSManagedObject  
{
}

@property (nonatomic, retain) NSNumber * Snooze;
@property (nonatomic, retain) NSNumber * AlarmID;
@property (nonatomic, retain) NSString * Label;
@property (nonatomic, retain) NSDate * Repeat;
@property (nonatomic, retain) NSDate * Time;
@property (nonatomic, retain) NSNumber * Enabled;
@property (nonatomic, retain) NSString * Song;
@property (nonatomic, retain) NSString * Sound;

@end

1. What's a good way to manage the Local Notifications my app schedules so that I can later retrieve those Local Notification objects and reschedule them if needed?
2. Is there a way to retrieve the Local Notifications that have been scheduled by your app?
3. If so, is there a way to identify them uniquely?

Thanks so much in advance for your help!

Gentry

Answer 1

To answer question #2 use scheduledLocalNotifications, which will get back to you NSArray of all notifications scheduled for your app.

To answer question #3 use userInfo property of UILocalNotification class. It's a dictionary and you can save anything you want there.

Spiritualism

This only allows you to efficiently find the database entry for any given notification. The other way around, finding the notification object for a given database entry, would require you to search through the scheduledLocalNotifications array. Is it possible to store a pointer in Core Data? Or is there no guarantee the notification remains at the same memory address? Not that searching through a small array is such a big deal. – Unveiling

scheduledLocalNotifications only retrieve UILocalNotifications with property repeatInterval different from nil. – Brassica

Answer 2

1. You can retrieve all the local notifications your app has scheduled using the UIApplication classes scheduledLocalNotifications method.

Helix